Abstract:
Energy consumption is continuously increasing around the world and this instigates research to find sustainable energy solutions. Demand for cooling is one of the reasons for increasing energy demand. This research is focused on the sustainable ways to use solar power to decrease energy demand. The study investigates the effect of mass and heat recovery process on the performance of solar heat driven adsorption cooling system. In this study, theoretical performance trends of a solar powered adsorption cooling system are investigated. In basic cycle, it was observed that the cooling capacity and coefficient of performance increases monotonically with the increase of collector area. Therefore, in order to investigate for the optimum collector area, performance based on different collector number and cycle time has been conducted. Based on these analysis, 14 collectors with 1000s half cycle time is considered to be optimum collector area and cycle time respectively with the base run condition for a typical hot day of April with direct solar coupling. In order to reduce cost and maximize system performance, a two bed solar driven conventional cooling system run by silica gel and water along with mass recovery process has been investigated numerically. In an adsorption refrigeration cycle, the pressure in adsorber and desorber are different. The mass recovery cycle utilizes those pressure differences to enhance the refrigerant mass circulation. Solar adsorption cooling appears to have a bright prospect in tropical region. Though it has a huge installation cost, its long term payback could be a factor of consideration. Mass recovery scheme increases Cycle Average Cooling Capacity (CACC) of the adsorption cooling system. Though mass recovery has no major effect on Coefficient of Performance (COPcycle) but it enhanced the working hour. To facilitate heat transfer, in heat recovery phase, water is circulated between two adsorbers maintaining the same mass flow rate. There is no water vapour mass transfer between system components during this phase. It is a semi continuous system operated with two adsorption beds. The fluid flows through two adsorbers and thus transfers heat from the heated adsorber to the cooled adsorber. The heat transfer between the two adsorbers is done adiabatically. The results show that the heat recovery operation between two adsorption beds increase the COP by nearly15% compared to the basic cycle system.
